Atypical sources of childhood lead poisoning in the United States: a systematic review from 1966-2006

Measurement of lead, mercury, and cadmium in blood donors in Canada

BACKGROUND

Fetal and neonatal exposure to lead is associated with irreversible adverse effects on neural development. There is no reliable threshold for lead effect, so limiting exposure is recommended. A significant correlation has been reported between post-transfusion blood lead level (BLL) in infants and lead levels in transfused RBC units. We measured levels of lead, mercury, and cadmium, in Canadian donor blood to investigate if concerning levels for neonatal transfusion exist.

STUDY DESIGN AND METHODS

Whole blood samples from blood donors (n = 2529) were shipped cold within 7 days of donation. All permanent blood donation clinics across Canada were sampled. Twelve of these permanent clinics and 8 mobile clinics with a greater potential for having higher lead or mercury levels were oversampled. Heavy metals were measured by inductively coupled plasma mass spectrometry.

RESULTS

Of all donations, 2.2% (lead) and 0.4% (mercury) had levels higher than the recommended thresholds for safe neonatal transfusion. BLLs were higher in males but there was no significant difference in the blood mercury levels of males versus females. Cadmium levels were higher in females. There was a positive correlation between donor age and levels of heavy metals, with lead having the strongest correlation (r = 0.47, p < .0001). Three clinics in close proximity to two lead-producing mines were among the clinics with the highest BLLs. Significantly higher blood mercury levels were observed in coastal clinics.

CONCLUSION

Our data on donor blood heavy metal levels supports considering blood transfusion as an exposure source to heavy metals and encourages informed selection of blood units for transfusion to vulnerable groups.

Investigating the Effectiveness of Exopolysaccharide-Producing Lactic Acid Bacteria in Biosorbing Lead (II), Attaching to Caco-2 Cells, and Provoking Antiinflammatory Responses

Lead is a common toxic heavy metal with harmful effects on the human body and is widely used in several industries. It can contaminate the environment by air and water emissions and can enter the human body through the respiratory tract, ingestion, or skin contact. Lead is considered as a persistent environmental pollutant, with a half-life of 30 days in the blood, and exists in the skeletal system for decades and causes damage to other systems. Biosorption is receiving increasing attention. Due to its high efficiency and economic value in removing heavy metals from the environment, a variety of biosorption methods can be used for the removal of heavy metals. Lactic acid bacteria (LAB) strains were capable of attaching to both human skin stratum corneum HaCaT cells and human rectal cancer Caco-2 cells. NBM-04-10-001 and NBM-01-07-003 significantly reduced the secretion of IL-6 and IL-8 after coculture with HaCaT cells. In the immune response of RAW264.7 mouse macrophages, high bacterial counts reduced the concentrations of IL-6 and TNF-α in a dose-dependent manner. The results of animal experiments revealed that feeding lead solution exerted no effect on the animal's food intake, and feeding PURE LAC NBM11 powder could effectively remove lead content in the blood. The group fed with PURE LAC NBM11 powder showed significantly less damage and lesions to liver cells. The LAB powder developed in this study has the potential to bind metals, preventing them from entering the body and protecting the host. LAB can be an ideal strain for future bioadsorption chelators.

Association between lead source exposure and blood lead levels in some lead manufacturing countries: A systematic review and meta-analysis

Lead is one of the 10 most toxic chemicals of greatest concern for its effects on public health. Predominantly, in undeveloped countries, high blood lead levels (BLLs) persist in the population. To develop intervention strategies that may reduce lead exposure in populations, it is a priority to know the sources of lead pollution. The objective of this critical review and meta-analysis is to assess whether there is an association between different sources of lead exposure and the mean difference in blood lead levels in people exposed. To identify the major lead source exposure, a statistical analysis was performed on selection studies. This investigation reveals the limited information available on the sources of lead in Mexico and other lead producer countries, such as Croatia, Ecuador, Brazil, South Korea, India, Nigeria, Turkey, and China. Meta-analysis could be performed only in battery, smelting mining, and glazed ceramic workers. Battery manufacturing workers have the highest mean difference level of lead in their blood worldwide. Mexico has the second highest mean difference BLL in battery workers in the world. An interesting difference between the mean difference in BLL in mining workers from uncontrolled industry (-39.38) and controlled industry (-5.68) was found. This difference highlighted the success of applying strict control of lead sources and community education to reduce BLL and its potential harmful effects on human health and the environment. Children living near mining sites have the highest mean difference BLL (-11.1). This analysis may aid in assessing the source of lead exposure associated with a range of BLLs in people. Furthermore, this review highlights several social and cultural patterns associated with lead exposure and lead levels in control populations. These results could help to develop international lead regulations and appropriate public health guidelines to protect people around the world.

Cognitive Impairment Induced by Lead Exposure during Lifespan: Mechanisms of Lead Neurotoxicity

Lead (Pb) is considered a strong environmental toxin with human health repercussions. Due to its widespread use and the number of people potentially exposed to different sources of this heavy metal, Pb intoxication is recognized as a public health problem in many countries. Exposure to Pb can occur through ingestion, inhalation, dermal, and transplacental routes. The magnitude of its effects depends on several toxicity conditions: lead speciation, doses, time, and age of exposure, among others. It has been demonstrated that Pb exposure induces stronger effects during early life. The central nervous system is especially vulnerable to Pb toxicity; Pb exposure is linked to cognitive impairment, executive function alterations, abnormal social behavior, and fine motor control perturbations. This review aims to provide a general view of the cognitive consequences associated with Pb exposure during early life as well as during adulthood. Additionally, it describes the neurotoxic mechanisms associated with cognitive impairment induced by Pb, which include neurochemical, molecular, and morphological changes that jointly could have a synergic effect on the cognitive performance.

Blood Lead Surveillance and Exposure Sources Among Alaska Children

CONTEXT

Nationally, the child lead poisoning prevention strategy focuses on children in low-income communities living in old housing with lead paint. In Alaska, however, only about 3% of existing homes were built before 1950 and 38% were built during 1950-1979. As such, lead paint in old housing is a less frequent source of exposure for Alaska children with elevated blood lead levels (EBLLs).

PROGRAM

The Alaska Department of Health and Social Services collects and maintains data for all blood lead level (BLL) tests in the state and is responsible for following up on EBLLs.

IMPLEMENTATION

The Alaska Department of Health and Social Services conducts telephone interviews with parents of children with an EBLL to identify and remove possible sources of lead from the child's environment and prevent subsequent exposure.

EVALUATION

This review summarizes the surveillance data on BLLs in Alaska children for 2011-2015 and describes the most commonly identified possible sources of childhood lead exposure statewide since 2011.

DISCUSSION

While the proportion of children in Alaska who received a BLL test during these years is low compared with other states and EBLL prevalence is low among children tested, several possible sources of exposure were identified among children with EBLLs, including nonpaint sources. This report summarizes the challenges of combatting childhood lead exposure in a rural state where housing is a less common exposure source and describes ongoing work to prevent childhood lead exposure in Alaska.

Unusual Domestic Source of Lead Poisoning

Non-occupational lead poisoning is not rare, mainly occurring in domestic situations in children, but also in adults. Lead poisoning was observed in a 65 years-old woman non-exposed to risk that caught our attention with a diagnostic suspicion of acute intermittent porphyria according to recurrent episodes of abdominal pain and neuropathy of upper limbs. Acute intermittent porphyria was excluded by a laboratory investigation that showed instead severe lead poisoning. After several thorough examinations of the domestic environment, the source of intoxication has been detected in some cooking pots that released high concentrations of lead. Ethylenediamine tetracetic acid disodium calcium therapy (three cycles) reduced consistently blood lead concentration and, after one year, neuropathy was almost entirely recovered.

Lead Pellet Ingestion in 3 Children: Another Source for Lead Toxicity

Acute ingestions of spherical lead ammunition foreign bodies such as bullets and lead shot can cause acute blood lead level elevations and clinical symptoms necessitating emergency department evaluations and sometimes treatment. This article presents 3 cases of children ingesting lead ammunition, all receiving gastrointestinal (GI) decontamination and chelation therapy for significantly elevated blood lead level. Case-specific exposures and treatments for the lead ammunitions are presented. Radiographs documented lead pellet ingestion in all 3 cases. Pediatric patients absorb lead from the GI tract more quickly than adults and may necessitate more urgent evaluation and treatment than adolescents/adults. More rapid GI absorption has the potential to result in possible irreversible neurotoxicity and neurocognitive deficits as well as behavioral changes. Failure of lead foreign bodies to pass from the GI tract may require more aggressive interventions for their removal to prevent ongoing absorption. Emergency health care providers should be aware of alternative lead sources besides the most common source of paint, as these lead foreign bodies also need urgent evaluation and possibly treatment.

Evaluation of the Blood Lead Screening Component of the Southern Nevada Childhood Lead Poisoning Prevention Program

CONTEXT

While public health programs and policies have worked to reduce lead exposure, lead poisoning remains a major preventable public health concern in the United States.

OBJECTIVE

In Clark County, Nevada, blood lead level (BLL) screening has historically been sparse. Thus, the purpose of this study was to evaluate the impact of the Southern Nevada Childhood Lead Poisoning & Prevention Program (CLPPP) in increasing screening efforts and identifying children with elevated blood lead levels (EBLLs).

MAIN OUTCOMES

The proportion of children screened after the implementation of the CLPPP and the number of children identified with detectable BLLs.

RESULTS

A total of 43 028 BLL results for children younger than 6 years were assessed from 2006 to 2011. More than 19% of children tested during the project period had a detectable BLL. The number of BLL tests for children younger than 6 years increased from 4180 in 2005-2006 to 9304 in just the second year of CLPPP implementation. Once the initial implementation grant was over and additional funding was unavailable, the BLL screening once again declined to 5541 in 2016-2017.

CONCLUSION

Evaluation of CLPPP activities suggests that outreach and education efforts, funded by the Centers for Disease Control and Prevention, played a significant role in increasing blood lead screening in Southern Nevada. However, despite these efforts, less than 5% of all children younger than 6 years were screened, which has declined further after the end of federal support.

Environmental factors associated with blood lead among newcomer women from South and East Asia in the Greater Toronto Area

BACKGROUND

Newcomers bring with them histories of environmental exposure in their home countries and may have different sources of lead (Pb) exposure compared to other residents of their adopted country.

AIMS

To describe past and current factors associated with Pb exposure and blood Pb among South and East Asian newcomer women of reproductive age in the Greater Toronto Area (GTA), Ontario, Canada.

METHODS

In collaboration with public health units and community organizations a community-based research model was utilized by recruiting peer researchers to assist in all aspects of the study. Blood samples were taken and phone interviews were conducted. Canadian Health Measures Survey (CHMS) cycles 1, 2, and 3 data was used to contextualize the distribution blood Pb levels. Multiple regression was applied to log-transformed blood lead measurements, using a hierarchical model building process.

RESULTS

In total, 211 participants were recruited from Bangladesh, China, India, Pakistan and Sri Lanka. The distribution of the blood Pb varied by country of origin, and higher blood Pb values were found above 75th percentile compared to the CHMS. Distal factors significantly influencing blood Pb concentrations related to life history, such as duration of stay in Canada (RR=0.91; 95% CI 0.86-0.97), living near agricultural fields (RR=0.78; 95% CI 0.62-0.93), and country of origin. Proximal factors with significant contribution were use of cosmetics, traditional remedies, and smoking cigarettes.

RECOMMENDATIONS

Different past and current exposures may be important in various newcomer populations, informing international stakeholders, public health agencies, and primary care practitioners to adapt health education and exposure reduction programs to consider pre- and post-migration factors.

Surma eye cosmetic in Afghanistan: a potential source of lead toxicity in children

Surma is a traditional eye cosmetic used as an eyeliner for infants in Afghanistan, as well as in many other countries in Asia, the Middle East, and Africa. Surma has been reported to contain lead and to be a potential source of lead toxicity in children, which can lead to permanent damage to multiple organ systems. To our knowledge, assessment for lead in surma found in Afghanistan has not been performed. We determined the quantitative lead content of a convenience sample of 10 surma products acquired in Afghanistan. Analysis revealed that 70% of surma samples contained high levels of lead (range 35-83%). The remaining samples contained low levels of lead (range 0.04-0.17%).

CONCLUSION

The majority of surma samples contained very high levels of lead, a troubling finding that could potentially correlate with lead toxicity in Afghan children. Making available lead-free surma alternatives and providing health education, for both healthcare professionals and the general population, in locations where surma use is prevalent and for those involved in care of refugees and immigrants from Afghanistan, may be strategies to prevent lead poisoning in children. What is Known: • Surma is a traditional cosmetic used as an eyeliner for infants in Afghanistan as well as in many countries in Asia, the Middle East, and Africa. • Surma has been reported to contain lead and to be a source of lead toxicity in children. What is New: • Assessment for lead content in surma found in Afghanistan has not been performed. • In this convenience sample of 10 surma products acquired in Afghanistan, 70% contained very high levels of lead.

Prevention of Childhood Lead Toxicity

Blood lead concentrations have decreased dramatically in US children over the past 4 decades, but too many children still live in housing with deteriorated lead-based paint and are at risk for lead exposure with resulting lead-associated cognitive impairment and behavioral problems. Evidence continues to accrue that commonly encountered blood lead concentrations, even those below 5 µg/dL (50 ppb), impair cognition; there is no identified threshold or safe level of lead in blood. From 2007 to 2010, approximately 2.6% of preschool children in the United States had a blood lead concentration ≥5 µg/dL (≥50 ppb), which represents about 535 000 US children 1 to 5 years of age. Evidence-based guidance is available for managing increased lead exposure in children, and reducing sources of lead in the environment, including lead in housing, soil, water, and consumer products, has been shown to be cost-beneficial. Primary prevention should be the focus of policy on childhood lead toxicity.

Use of lead-glazed ceramic ware and lead-based folk remedies in a rural community of Baja California, Mexico

Background:

Lead exposure from lead-glazed ceramics (LGCs) and traditional folk remedies have been identified as significant sources of elevated blood lead levels in Mexico and the United States. This study took place from 2005 to 2012 in a rural community in Baja California, Mexico.

Objectives:

1) Investigate the knowledge, attitudes, and practices related to lead and lead exposures from LGCs and two lead-based folk remedies ( azarcon and greta); and 2) evaluate a pilot intervention to provide alternative lead-safe cookware.

Methods:

A baseline household survey was conducted in 2005, followed by the pilot intervention in 2006, and follow-up surveys in 2007 and 2012. For the pilot intervention, families who reported using LGCs were given lead-safe alternative cookware to try and its acceptance was evaluated in the following year.

Results:

The community was mostly of indigenous background from Oaxaca and a high proportion of households had young children. In 2006, all participants using traditional ceramic ware at the time ( n = 48) accepted lead-safe alternative cookware to try, and 97% reported that they were willing to exchange traditional ceramic ware for lead-safe alternatives. The use of ceramic cookware decreased from over 90% during respondents’ childhood household use in Oaxaca to 47% in 2006 among households in Baja California, and further reduced to 16.8% in 2012. While empacho, a folk illness, was widely recognized as an intestinal disorder, there was almost universal unfamiliarity with the use and knowledge of azarcon and greta for its treatment.

Conclusion:

This pilot evaluation provides evidence 1) for an effective and innovative strategy to reduce lead exposure from LGCs and 2) of the feasibility of substituting lead-free alternative cookware for traditional ceramic ware in a rural indigenous community, when delivered in a culturally appropriate manner with health education. This strategy could complement other approaches to reduce exposure to lead from LGCs.

Lead in candy consumed and blood lead levels of children living in Mexico City

BACKGROUND

Recent studies have shown that lead exposure continues to pose a health risk in Mexico. Children are a vulnerable population for lead effects and Mexican candy has been found to be a source of exposure in children. There are no previous studies that estimates lead concentrations in candy that children living in Mexico City consume and its association with their blood lead level.

OBJECTIVES

To evaluate whether there is an association between reported recent consumption of candies identified to have lead, and blood lead levels among children in Mexico City.

METHODS

A subsample of 171 children ages 2-6 years old, from the Early Life Exposure in Mexico to Environmental Toxicants (ELEMENT) cohort study was assessed between June 2006 and July 2007. The candy reported most frequently were analyzed for lead using ICP-MS. The total weekly intake of lead through the consumption of candy in the previous week was calculated. Capillary blood lead levels (BLL) were measured using LeadCare (anodic stripping voltammetry).

RESULTS

Lead concentrations ≥0.1ppm, the FDA permitted level (range: 0.13-0.7ppm) were found in 6 samples out of 138 samples from 44 different brands of candy. Median BLL in children was 4.5µg/dl. After adjusting for child's sex, age, BMI, maternal education & occupation, milk consumption, sucking the candy wrapper, use of lead-glazed pottery, child exposure behavior, living near a lead exposure site and use of folk remedies, an increase of 1µg of lead ingested through candy per week was associated with 3% change (95% CI: 0.1%, 5.2%) in BLL.

CONCLUSIONS

Although lead concentrations in candy were mostly below the FDA permitted level, high lead concentrations were detected in 4% of the candy samples and 12% of brands analyzed. Although candy intake was modestly associated with children's BLL, lead should not be found in consumer products, especially in candy that children can consume due to the well documented long-lasting effect of lead exposure.

Children intoxications: what is abuse and what is not abuse

The curiosity and the natural tendency to explore the environment put young children at an increased risk of poisoning over older children and adults. Poisonings are a significant area of concern from 1 year of age and progressively contribute more to overall rates of morbidity and mortality until children reach adulthood. Particularly, the abuse of children by poisoning is also highly common with thousands of fatalities. A practical strategy is presented that aims to alert health, forensic, and law enforcement professionals to this problem and to demystify the preconception that it is a rare form of abuse or neglect. Compounds that are foreign to a living organism (xenobiotics) and those present within body (endobiotics), mainly involved in children intoxications and contextual examples related to exposure are also reviewed. Particular concern is given to concepts in the field of children poisoning. The described history and the clinical and toxicological evaluation are discussed, and harmonized protocols regarding correct procedures for sample collection to forensic toxicological analysis are proposed. Since children are particularly vulnerable to the toxic effects of high doses of xenobiotics and endobiotics, special consideration on the preparation of the environment that surrounds children in order minimize all possible risks will be also considered.

An evaluation of lead concentrations in imported hot sauces

In the last decade, the U.S. Food and Drug Administration (FDA) has issued several warnings and recalls for food products that exceed FDA standards for lead. Products containing chili peppers and salt were often suspected as sources of lead contamination, and included items such as candy that are routinely investigated. However, products such as hot sauces that contain similar ingredients have not been the focus of evaluations. This study quantified lead concentrations in imported hot sauces, evaluated product compliance to existing United States standards, and calculated potential dietary lead exposure for children using the Integrated Exposure Uptake Biokinetic Model. Finally, recommendations for reducing the risk of lead exposure from hot sauces are provided. Twenty-five (25) bottles of imported hot sauces manufactured in Mexico and South America were purchased in Clark County, Nevada. All hot sauces were analyzed for lead concentrations, pH, and leaded packaging. Hot sauces were analyzed by inductively coupled plasma mass spectrometry and packaging was analyzed using x-ray fluorescence technology. Four brands of hot sauces (16%) exceeded 0.1 ppm lead, the current FDA action level for lead in candy. Hot sauces with lead concentrations >0.1 ppm lead contained salt and were manufactured in Mexico. Subsequent analysis of additional lots of hot sauces exceeding 0.1 ppm lead revealed inconsistent lead concentrations between and within manufacturer lots. The lead concentrations of the plastic hot sauce lids ranged from below the limit of detection to 2,028 ppm lead. There was no association between lead concentrations in hot sauces and pepper type. These results indicate the need for more rigorous screening protocols for products imported from Mexico, the establishment of an applicable standard for hot sauce, and resources to allow for the enforcement of existing food safety policies. The data reported herein represent the first known investigation of lead concentrations in hot sauces.

Bioremediation and tolerance of humans to heavy metals through microbial processes: a potential role for probiotics?

The food and water we consume are often contaminated with a range of chemicals and heavy metals, such as lead, cadmium, arsenic, chromium, and mercury, that are associated with numerous diseases. Although heavy-metal exposure and contamination are not a recent phenomenon, the concentration of metals and the exposure to populations remain major issues despite efforts at remediation. The ability to prevent and manage this problem is still a subject of much debate, with many technologies ineffective and others too expensive for practical large-scale use, especially for developing nations where major pollution occurs. This has led researchers to seek alternative solutions for decontaminating environmental sites and humans themselves. A number of environmental microorganisms have long been known for their ability to bind metals, but less well appreciated are human gastrointestinal bacteria. Species such as Lactobacillus, present in the human mouth, gut, and vagina and in fermented foods, have the ability to bind and detoxify some of these substances. This review examines the current understanding of detoxication mechanisms of lactobacilli and how, in the future, humans and animals might benefit from these organisms in remediating environmental contamination of food.

Successful treatment of extreme acute lead intoxication

Severe acute lead intoxications are rare and are associated with accidental or purposeful ingestion. There were only few cases of severe to fatal poisonings reported in literature in children. We report a case of acute lead intoxication in a child with extremely high lead blood level of 20.4 μmol/L (422.7 μg/dL), who was treated with chelation and in whom significant organ dysfunction did not develop. Documented significant high level above 3.37 μmol/L (corresponding to 70 μg/dL) in this patient persisted for approximately 24 h. Adequate, single or combined chelatation therapy in early phase of acute lead poisoning is essential for the further patient’s outcome.